The present invention relates to a method of processing a signal having a monochromatic signal component with the aid of a digital filter for suppressing the monochromatic signal component.
Such an electrical signal is encountered, for example, in communication transmissions that are effected with the aid of a so-called carrier signal. The carrier signal in a communications receiver serves merely to tune the receiver to a desired communications transmitter. For an evaluation of the data, the carrier signal must be suppressed at the receiving end since it contains no communication information. In this context, the carrier signal can also be called the monochromatic signal component of the entire signal which should be suppressed as well as possible by means of a filter, for example, a digital filter. Such a filter has a more or less long transient period. The transient period, however, generally does not pose a problem since it at most prevents evaluation of the data for a short time, for example whenever the communications receiver is tuned from a first carrier signal (first transmitter) to a second carrier signal (second transmitter). In that case reliable evaluation of the data of the second transmitter, mentioned as an example, can take place only after the transient period of the filter for the monochromatic signal component. If the carrier signal changes only rarely, the transient period of the filter involved is also negligible. If, however, the carrier signal is interrupted relatively frequently, for example, due to switching processes, the transient period of the filter may cause an annoying loss of a considerable portion of the communication information.